[Python-modules-commits] r11501 - in packages/python-ctypeslib/trunk/debian (examples.Debian)

[mrbeige-guest at users.alioth.debian.org]

    Date: Tuesday, February 2, 2010 @ 16:56:02
  Author: mrbeige-guest
Revision: 11501

Update examples.Debian

Modified:
  packages/python-ctypeslib/trunk/debian/examples.Debian

Modified: packages/python-ctypeslib/trunk/debian/examples.Debian
===================================================================
--- packages/python-ctypeslib/trunk/debian/examples.Debian	2010-02-02 16:12:00 UTC (rev 11500)
+++ packages/python-ctypeslib/trunk/debian/examples.Debian	2010-02-02 16:56:02 UTC (rev 11501)
@@ -24,36 +24,62 @@
 #
 # When you pass the -l argument, it will scan the libary for
 # executable symbols.  If it finds them, it will automatically set up
-# to run, using ctypes, from that library.
+# to run, using ctypes, from that library.  In this example, math_c.py
+# becomes a module which automatically interface to libm
 
 h2xml /usr/include/math.h -c -o math_c.xml
 xml2py math_c.xml -o math_c.py -l /lib/libm.so.6
 
+# In math_c.py:
+# 
+# | _libraries['/lib/libm.so.6'] = CDLL('/lib/libm.so.6')
+# | 
+# | log10 = _libraries['/lib/libm.so.6'].log10
+# | log10.restype = c_double
+# | log10.argtypes = [c_double]
+#
+# which is an automatic ctypes interface to log10 in libm
+# To use it:
 
+python2.6
+>>> import math_c
+>>> math_c.log10(100)
+2.0
 
+
+
 ########################################
 
-
-# Let's work on time.h:
+# Let's play with time.h (works on python2.5):
 #
-# We get a lot of stuff, for example, the definition of the C structure 
-# "struct tm" is automatically created, for example:
+# We get a lot of stuff, for example, the ctypes definition of the C
+# structure "struct tm" is automatically created, for example:
 #
-# class tm(Structure):
-#     pass
-# tm._fields_ = [
-#     ('tm_sec', c_int),
-#     ('tm_min', c_int),
-#     ('tm_hour', c_int),
-#     ('tm_mday', c_int),
-#     ('tm_mon', c_int),
-#     ('tm_year', c_int),
-#     ('tm_wday', c_int),
-#     ('tm_yday', c_int),
-#     ('tm_isdst', c_int),
-#     ('tm_gmtoff', c_long),
-#     ('tm_zone', STRING),
+# | class tm(Structure):
+# |     pass
+# | tm._fields_ = [
+# |     ('tm_sec', c_int),
+# |     ('tm_min', c_int),
+# |     ('tm_hour', c_int),
+# |     ('tm_mday', c_int),
+# |     ('tm_mon', c_int),
+# |     ('tm_year', c_int),
+# |     ('tm_wday', c_int),
+# |     ('tm_yday', c_int),
+# |     ('tm_isdst', c_int),
+# |     ('tm_gmtoff', c_long),
+# |     ('tm_zone', STRING),
+# | ]
+#
+# We also have various functions defined:
+# 
+# | _libraries['/lib/libc.so.6'] = CDLL('/lib/libc.so.6')
+# | 
+# | strptime = _libraries['/lib/libc.so.6'].strptime
+# | strptime.restype = STRING
+# | strptime.argtypes = [STRING, STRING, POINTER(tm)]
 
+
 # We use '-l /lib/libc.so.6', so that we automaticall set up to run
 # defined functions from libc.so.6, using ctypes
 
@@ -63,11 +89,14 @@
 man strptime
 python
 >>> import time_c
-#  Initialize a `struct tm` object to use as the return values of our
-#  function call.
+# Initialize a `struct tm` object to use as the return values of our
+# function call.
 >>> tm = time_c.tm()
+# Call strptime, with two strings and a pointer to the struct_tm.  Read
+# the manual page on strptime to understand the return value.
 >>> time_c.strptime("Dec 19, 1985", "%b %d, %Y", tm)
 ''
+# And our data structure is filled in:
 >>> tm.tm_yday
 352
 >>> tm.tm_year